Glossary Definition for Swallow-Counter

Glossary Term: Swallow-Counter

Definition

The Swallow Counter is one of the three building blocks (swallow counter, main counter, and dual-modulus prescaler) that constitute the programmable divider commonly used in modern frequency synthesizers.

The swallow counter is used to control the dual-modulus prescaler which is set to either N or (N+1). At the initial reset state, the prescaler is set to a divide ratio of (N+1), but the swallow counter will change this divide ratio to N when it finishes counting S number of cycles.

The Swallow Counter gets its name from the idea that it "swallows" 1 from (N+1) of the dual-modulus prescaler.